相关论文: Optically and electrically excited intermediate el…
Layered transition metal dichalcogenides (TMDCs) host a variety of strongly bound exciton complexes that control the optical properties in these materials. Apart from spin and valley, layer index provides an additional degree of freedom in…
The two-dimensional organic conductor $\alpha$-(BEDT-TTF)$_2$I$_3$ undergoes a metal-insulator transition at $T_{\rm CO}=135$ K due to electronic charge ordering. We have conducted time-resolved investigations of its electronic properties…
Excitons are composite bosons that can feature spin singlet and triplet states. In usual semiconductors, without an additional spin-flip mechanism, triplet excitons are extremely inefficient optical emitters. Large spin-orbit coupling in…
Organic light-emitting diodes (OLEDs) are central to modern display technologies and are promising candidates for low-cost energy-efficient lighting. Their performance is determined by numerous, intricate fabrication parameters, but not…
Density functional theory (DFT) has greatly expanded our ability to affordably compute and understand electronic ground states, by replacing intractable {\em ab initio} calculations by models based on paradigmatic physics from high- and…
We study the energy spectra of bound states in quantum dots (QDs) formed by an electrostatic potential in two-dimensional topological insulator (TI) and their transformation with changes in QD depth and radius. It is found that, unlike a…
TADF emitter performance depends on both thermodynamic and kinetic factors. We analyze 747 experimentally known TADF molecules computationally to extract quantitative design guidelines. Using a validated xTB-based workflow, we examine how…
We have studied the excited states of a one-dimensional donor dimer array by using time-dependent Hartree-Fock and density-functional theories. We find that tuning the inter-donor distances can induce a topological phase transition from a…
The blue emission of polyfluorene (PF) based light-emitting diodes (LEDs) is known to degrade due to a low energy green emission, which hitherto has been attributed to oxidative defects. By studying the electroluminescence from ethyl-hexyl…
Several modern technologies for energy storage and conversion are based on the screening of electric charge on the surface of porous electrodes by ions in an adjacent electrolyte. This so-called electric double layer (EDL) exhibits an…
A phenomenological coupled exciton model is proposed in order to characterize optical excitations in extended dendrimers. An onsite exciton state is assigned at each phenyl rings and a nearest neighbor hopping integral which obeys the…
We investigate experimentally and theoretically the coherent and incoherent processes in open 3-level ladder systems in room temperature gases and identify in which regime electromagnetically induced transparency (EIT) occurs. The…
In organic solar cells, photogenerated singlet excitons form charge transfer (CT) complexes, which subsequently split into free charge carriers. Here, we consider the contributions of excess energy and molecular quadrupole moments to the…
Colloidal semiconductor quantum dots are robust emitters implemented in numerous prototype and commercial optoelectronic devices. However, active fluorescence color tuning, achieved so far by electric-field induced Stark effect, has been…
We present a theoretical description of femtosecond laser induced dynamics of the hydrogen molecule and of singly ionised sodium dimers, based on a real-space, real-time, implementation of time-dependent density functional theory (TDDFT).…
Recently, many exotic electronic states, such as quantum spin liquid (QSL) and superconductivity (SC), have been extensively discovered and introduced in layered transition metal dichalcogenides 1T-TaS2 by controlling their complex…
The remarkably strong Coulomb interaction in atomically thin transition metal dichalcogenides (TMDs) results in an extraordinarily rich many-particle physics including the formation of tightly bound excitons. Besides optically accessible…
The efficiency of an organic light-emitting diode (OLED) is fundamentally governed by the spin of recombining electron-hole pairs (singlet and triplet excitons), since triplets cannot usually emit light. The singlet-triplet energy gap, a…
Photoinduced charge-transfer processes play a key role for novel photovoltaic phenomena and devices. Thus, the development of ab initio methods that allow for an accurate and computationally inexpensive treatment of charge-transfer…
We designed and synthesized a new organic light-emitting diode (OLED) emitter, SBABz4, containing spiro-biacridine donor (D) in the core surrounded by two benzonitrile acceptors (A). The dual A-DxD-A structure is shown to provide pure-blue…